Cytokines play an important role in the CNS in the modulations of dopaminergic, serotonergic, noradrenergic and cholinergic systems. Interleukin-6 (IL-6) is the cytokine released from astrocytes, microglia and neurons in physiological and some pathologic conditions. IL-6 has neuromodulating effect in dopaminergic and serotonergic systems of the brain. Moreover, IL-6 influences survival of dopaminergic neurons, neurite outgrowth, and glial differentiation in the developing neural tissues. From this point of view, the gene for IL-6 is a possible candidate gene for the disposition to the alcohol dependence. We investigated the relationship between the G/C -174 polymorphism of the IL-6 gene and alcohol dependence in 281 alcoholics and 242 control subjects. The significant difference in G allele frequency between alcoholic group (0,52) and control group (0,59) was found (p<0,03). Our work is the first study that found the association between the alcoholism and the polymorphism of the IL-6 gene. The background of the relationship between IL-6 gene and alcoholism is discussed.

        Key words: alcoholism, interleukin-6, association study, polymorphism.